Disposable diapers are well-known articles of manufacture which are designed to be worn by infants and incontinent persons. Disposable diapers are worn about the lower torso of the user and are intended to absorb and contain voided urine and feces thereby preventing the soiling, wetting, or similar contamination of articles (e.g., clothing, bedding, other persons, etc.) which may come into contact with such diaper in use.
There are numerous executions of disposable diapers available in the industry which generally comprise an absorbent core encased between a liquid permeable user-contacting topsheet and a liquid impermeable backsheet. Additionally, numerous disposable diapers are available in the industry which feature elastic means formed along that portion of the disposable diaper which contacts the wearer's thighs to thereby provide elasticized leg openings for such diaper in use. For example, U.S. Pat. No. 3,860,003, which issued to K. B. Buell on Jan. 14, 1975 discloses an integral disposable diaper which includes opposite, flexible side flaps in the crotch area of the diaper having an elastic member secured to each of such side flaps to provide an elasticized, contractible line through the side flaps, making them compliant and forming effective seals about the wearer's legs. The Buell elastic members are operatively associated with the side flaps so that in a normally unrestrained configuration, the elastic member effectively gathers the side flap material thereabout to provide an elasticized-contractible line through the side flaps adjacent the outer lateral edge thereof. A disposable diaper featuring an elastically constricted crotch section is shown in U.S. Pat. No. 4,050,462, which issued to Woon et al. on Sept. 27, 1977. The Woon et al. diaper comprises a crotch section disposed between two opposite waist sections, with the crotch section being longitudinally constricted by elastic means secured to the backing sheet adajcent each of the side edges of the crotch portion. The elastic means is designed such that when in the non-extended condition, a plurality of gross, transverse rugosities are provided across the width of the crotch section of the diaper. These transverse rugosities thereby reduce the length of the crotch section without reducing the amount of the absorbent material therein, thereby effectively increasing the absorbent capacity per unit area of the diaper in its crotch area.
Other prior art has been aimed at shaping the inner absorbent pad within the disposable diaper to reduce bulk in the crotch area and improve the diaper's fit about the wearer's leg. For example, U.S. Pat. No. 4,336,803, which issued to F. L. Repke on June 29, 1982, concerns a disposable diaper having a shaped absorbent pad which reduces the bulk between the wearer's legs while allegedly maintaining excellent absorptive efficiency of such absorbent pad. Specifically, the Repke shaped absorbent pad is to have a series of indentations formed along its opposite longitudinal edges to provide a short area between one end of the pad and the deepest portion of the indentations, and a long area between the opposite area of the pad wherein a second indentation is formed. The short portion of the absorbent pad is to be positioned in the front of the baby, and the longer portion is to extend between the babies legs and behind the buttocks. Such shape allegedly reduces bulk without negatively affecting abosrptive capacity of the absorbent core. The Repke U.S. Pat. No. 4,336,803 diaper further includes an elastic member along the longitudinal sides of the abosrbent core to provide a tight fit about the baby's legs. Similarly, U.S. Pat. No. 4,430,086, which issued to F. L. Repke on Feb. 7, 1984 discloses a disposable diaper which can include a shaped inner absorbent core; and comprising gathering means having at least two separately extending elastic elements. In particular, the Repke U.S. Pat. No. 4,430,086 diaper includes a pair of elastic strips extending along the opposite longitudinal sides of the diaper which provide two separate and distinct elastic gathers designed to define two separate lines of gasketing around the wearer's legs. The separation of the distinct elastic elements allegedly provides a greater area over which the elastic forces are distributed thereby minimizing the constrictive effect on the wearer's legs.
Despite all the prior work done in this area, there remain problems in optimizing the fit of disposable diapers while at the same time reducing the amount of urine leakage at the legs. Additionally, prior art diapers tend to sag downwardly and bunch inwardly in the crotch area during use, further negatively affecting the diaper's comfort and fit as well as its containment and absorptive functions. Elasticized leg openings tend to migrate into the wearer's leg creases in the crotch area thereby augmenting the sagging/bunching problem and reducing the ability of such prior art diapers to contain voided substances.